[alsa-devel] [PATCH] ASoC: rsnd: remove unnecessary static in rsnd_ssiu_probe()
Remove unnecessary static on local variable ops. Such variable is initialized before being used, on every execution path throughout the function. The static has no benefit and, removing it reduces the code size.
This issue was detected using Coccinelle and the following semantic patch:
@bad exists@ position p; identifier x; type T; @@
static T x@p; ... x = <+...x...+>
@@ identifier x; expression e; type T; position p != bad.p; @@
-static T x@p; ... when != x when strict ?x = e;
In the following log you can see the difference in the code size. Also, there is a significant difference in the bss segment. This log is the output of the size command, before and after the code change:
before: text data bss dec hex filename 3211 680 64 3955 f73 sound/soc/sh/rcar/ssiu.o
after: text data bss dec hex filename 3207 592 0 3799 ed7 sound/soc/sh/rcar/ssiu.o
Signed-off-by: Gustavo A. R. Silva gustavo@embeddedor.com --- sound/soc/sh/rcar/ssiu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/soc/sh/rcar/ssiu.c b/sound/soc/sh/rcar/ssiu.c index bed2c9c..4d94875 100644 --- a/sound/soc/sh/rcar/ssiu.c +++ b/sound/soc/sh/rcar/ssiu.c @@ -250,7 +250,7 @@ int rsnd_ssiu_probe(struct rsnd_priv *priv) { struct device *dev = rsnd_priv_to_dev(priv); struct rsnd_ssiu *ssiu; - static struct rsnd_mod_ops *ops; + struct rsnd_mod_ops *ops; int i, nr, ret;
/* same number to SSI */
On Mon, 2017-07-17 at 10:30 -0500, Gustavo A. R. Silva wrote:
Remove unnecessary static on local variable ops. Such variable is initialized before being used, on every execution path throughout the function. The static has no benefit and, removing it reduces the code size.
[]
In the following log you can see the difference in the code size. Also, there is a significant difference in the bss segment. This log is the output of the size command, before and after the code change:
before: text data bss dec hex filename 3211 680 64 3955 f73 sound/soc/sh/rcar/ssiu.o
after: text data bss dec hex filename 3207 592 0 3799 ed7 sound/soc/sh/rcar/ssiu.o
[]
diff --git a/sound/soc/sh/rcar/ssiu.c b/sound/soc/sh/rcar/ssiu.c
[]
@@ -250,7 +250,7 @@ int rsnd_ssiu_probe(struct rsnd_priv *priv) { struct device *dev = rsnd_priv_to_dev(priv); struct rsnd_ssiu *ssiu;
- static struct rsnd_mod_ops *ops;
struct rsnd_mod_ops *ops; int i, nr, ret;
/* same number to SSI */
I'm not an sh user anymore, but it's curious to me why the static removal has such a large impact on data size.
Is this for an allyesconfig with debug symbols?
btw: this does compile for x86 and those sizes seem more sensible.
$ size sound/soc/sh/rcar/ssiu.o* text data bss dec hex filename 1950 248 0 2198 896 sound/soc/sh/rcar/ssiu.o.defconfig.new 1950 248 8 2206 89e sound/soc/sh/rcar/ssiu.o.defconfig.old 2692 248 0 2940 b7c sound/soc/sh/rcar/ssiu.o.allyesconfig.new 2692 248 8 2948 b84 sound/soc/sh/rcar/ssiu.o.allyesconfig.old
participants (2)
-
Gustavo A. R. Silva -
Joe Perches